Celiac disease is characterized by an immune response to glutin and similar proteins found in wheat, rye and barley. For individuals with celiac disease, eating glutin results in an inflammed small intestine, diarrhea and fatigue, among other symptoms. It’s estimated that about 1% of all Americans suffer from celiac disease. Given the heritability of the [Read More →]
Variable expressivity and epistasis go hand in hand when talking about genetic disorders. Knowing what they mean will help you really understand the kind of complications researchers are up against. In this article I’ll illustrate these concepts using a recently published paper on the causes of autism as an example. One of the genetic risk [Read More →]
We know that lots of genes are involved in cancer progression. For example, you’ve probably read something like “scientists have found the gene for such-and-such cancer” or something similar. What does that really mean? Are there really genes which cause cancer? And why do we have those genes anyways, if that’s all they do? Generally [Read More →]
One of the most striking features about tumors is that they have many, many mutations, all over the genome. To make things more complicated, not every cell in a tumor will have the same set of mutations. A tumor is a very heterogeneous (mixed) bunch of cells. The presence of so many mutations led researchers [Read More →]
A fascinating thing about DNA replication is that the actual process lacks the ability to replicate the very ends of chromosomes. That means chromosomes should get shorter with every round of cell division (DNA replication), but they remain more or less the same length, getting gradually shorter with aging. The natural shortening of chromosomes is [Read More →]
When geneticists want to uncover genetic associations for a particular disease, they can compare specific genetic variants (alleles) present in a large group of individuals with the disease to those present in a large group without the disease. The basic logic is that variants over-represented- or only found in- the disease population, are associated with [Read More →]
A striking discovery in medical genetics is that some apparently disparate diseases may have similar underlying genetic dysfunctions. Take for example, familial dysautonomia (FD), described in Slaugenhaupt et al. (2001): The loss of neuronal function in FD has many repercussions, with patients displaying gastrointestinal dysfunction, abnormal respiratory responses to hypoxic and hypercarbic states, scoliosis, gastroesophageal [Read More →]
There has been quite a buzz circulating about the possibility of therapeutic gene silencing strategies. Today I want to take a first look at what these therapies mean. One great example where gene silencing could be used is in polyglutamine disorders. This includes several disorders where genes accumulate, by replication errors, a repeat expansion of [Read More →]
A study published in this month’s issue of Nature Genetics may provide insight into the future techniques of personalized medicine. The articles deals with technical advancements and a proof-of-principle study in identifying the causes underlying rare Mendelian disorders. The techniques involved re-sequencing (another name for next-generation sequencing and massively parallel sequencing) of the exome. That [Read More →]
Over the past ten years dozens of animals have seen their genomes sequenced. With the completion of each project, researchers have been eager to hear what new insights the genome of that animal has given us. The latest animal to reach the ranks of database legacy is the panda (or more specifically Jing Jing of [Read More →]
